Add balsamic vinegar to a large saute pan or skillet on medium-high heat. You'll need about 4 times balsamic as you think you'll need to dress the salad. It's reduces, hence the name. :) Bring it to boil. Once it's boiling reduce it to a simmer until it's almost as thick as you want it. It will keep reducing once it's off the heat. You can make this before hand and let it sit before you dress the salad. It will stay thick.

Drizzle the reduction over the veggies and fruits (and cheese). Add a pinch of salt. Depending on how wet you like the salad, you can add a bit of olive oil and more balsamic if you like. I usually add just a bit of olive oil and only the reduction. I like to really taste the veggies in my salads.